1. Field of the Invention
The present invention relates to an actuator arm assembly that grounds a head of a hard disk drive.
2. Background Information
Hard disk drives contain a plurality of magnetic heads that are coupled to rotating disks. The heads can magnetize and sense the magnetic fields of the disk to write and read data, respectively. The heads each have an air bearing surface that cooperates with a flow of air generated by the rotating disk to create an air bearing. The air bearing prevents mechanical wear between the head and the disk.
To facilitate formation of the air bearing the head is typically attached to a gimbal that pivots about a flexure arm. The flexure arm is cantilevered from the end of an actuator arm. The actuator arm has a voice coil motor that moves the heads across the surfaces of the disks.
The flexure arms are attached to the actuator arm by swagging the flexures into corresponding openings in the arm. The flexures may also have tabs that extend into corresponding slots of the actuator arm. The tabs are held in place with a non-conductive epoxy.
The output signals of the heads are amplified by a pre-amplifier circuit of the drive. The pre-amplifier circuit is connected to the heads by wires and/or flexible circuits that are attached to the flexures. The heads may be electrically grounded to the actuator arm through the flexures. The electrical path from the flexures to the actuator arm is limited to the area near the swage opening. It has been found that this area can be a relatively unreliable ground path resulting in a “floating” ground plane for the heads. A floating ground may degrade the performance of the drive.